硬盘在 BIOS 中报告不正确的大小

我有一台带有软件 RAID 系统的服务器。

阵列中有 4 个磁盘：
4 x 4TB 型号WD40EFRX -68WT0N0

我注意到操作系统报告其中一个磁盘为 3TB，所以我重新启动并检查了 BIOS，它也报告了 3TB。而它为其他人报告 4TB。

物理磁盘上的贴纸上写着 4TB，就像其他 3 个一样。这个磁盘已经在服务器中使用了几个月，没有任何问题。我最近所做的唯一更改是更新操作系统（在 RAID 之外的驱动器上）。

我将更换磁盘，但想知道是否有人以前见过这个以及是否有修复。它可能是硬盘控制器、主板/bios (MSI/AMI) 还是其他什么？我把驱动器放在另一台机器上，那里的 BIOS 也报告 3TB。

为什么它正好是 3TB 而不是 4？不知何故似乎太精确了。

有关驱动器的更多详细信息：SATA、WD Red(tm)、NASware(tm) 3.0

附加：

根据@shodanshok 的要求，这里是 hdparm 和 smartctl 的输出。看起来启用了主机保护区，并使用了 1/4 的驱动器。

$ sudo hdparm -N /dev/sda

/dev/sda:
max sectors   = 5860577134/7814037168, HPA is enabled

这可能是意外设置的还是由操作系统安装以某种方式设置的？

这是 smartctl 的输出：

$ sudo smartctl -a /dev/sda
 smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.19.0-32-generic] (local build)
 Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

 === START OF INFORMATION SECTION ===
 Device Model:     WDC WD40EFRX-68WT0N0
 Serial Number:    WD-WCC4E5RZJJUE
 LU WWN Device Id: 5 0014ee 2b7895291
 Firmware Version: 82.00A82
 User Capacity:    3,000,615,492,608 bytes [3.00 TB]
 Sector Sizes:     512 bytes logical, 4096 bytes physical
 Rotation Rate:    5400 rpm
 Device is:        Not in smartctl database [for details use: -P showall]
 ATA Version is:   ACS-2 (minor revision not indicated)
 SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
 Local Time is:    Thu Apr 14 13:58:53 2016 IST
 SMART support is: Available - device has SMART capability.
 SMART support is: Enabled

 === START OF READ SMART DATA SECTION ===
 SMART overall-health self-assessment test result: PASSED

 General SMART Values:
 Offline data collection status:  (0x00)   Offline data collection activity
                                           was never started.
                                           Auto Offline Data Collection: Disabled.
 Self-test execution status:      (   0)   The previous self-test routine completed
                                           without error or no self-test has ever 
                                           been run.
 Total time to complete Offline 
 data collection:                  (53280) seconds.
 Offline data collection
 capabilities:                      (0x7b) SMART execute Offline immediate.
                                           Auto Offline data collection on/off support.
                                           Suspend Offline collection upon new
                                           command.
                                           Offline surface scan supported.
                                           Self-test supported.
                                           Conveyance Self-test supported.
                                           Selective Self-test supported.
 SMART capabilities:             (0x0003)  Saves SMART data before entering
                                           power-saving mode.
                                           Supports SMART auto save timer.
 Error logging capability:         (0x01)  Error logging supported.
                                           General Purpose Logging supported.
 Short self-test routine 
 recommended polling time:          (   2) minutes.
 Extended self-test routine
 recommended polling time:          ( 532) minutes.
 Conveyance self-test routine
 recommended polling time:          (   5) minutes.
 SCT capabilities:                (0x703d) SCT Status supported.
                                           SCT Error Recovery Control supported.
                                           SCT Feature Control supported.
                                           SCT Data Table supported.

 SMART Attributes Data Structure revision number: 16
 Vendor Specific SMART Attributes with Thresholds:
 ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
   1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always       -       0
   3 Spin_Up_Time            0x0027   175   175   021    Pre-fail  Always       -       8241
   4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       14
   5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
   7 Seek_Error_Rate         0x002e   200   200   000    Old_age   Always       -       0
   9 Power_On_Hours          0x0032   098   098   000    Old_age   Always       -       1992
  10 Spin_Retry_Count        0x0032   100   253   000    Old_age   Always       -       0
  11 Calibration_Retry_Count 0x0032   100   253   000    Old_age   Always       -       0
  12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       14
 192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       9
 193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       1830
 194 Temperature_Celsius     0x0022   114   108   000    Old_age   Always       -       38
 196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
 197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       0
 198 Offline_Uncorrectable   0x0030   100   253   000    Old_age   Offline      -       0
 199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
 200 Multi_Zone_Error_Rate   0x0008   100   253   000    Old_age   Offline      -       0

 SMART Error Log Version: 1
 No Errors Logged

 SMART Self-test log structure revision number 1
 No self-tests have been logged.  [To run self-tests, use: smartctl -t]


 SMART Selective self-test log data structure revision number 1
  SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
     1        0        0  Not_testing
     2        0        0  Not_testing
     3        0        0  Not_testing
     4        0        0  Not_testing
     5        0        0  Not_testing
 Selective self-test flags (0x0):
   After scanning selected spans, do NOT read-scan remainder of disk.
 If Selective self-test is pending on power-up, resume after 0 minute delay.